Automatic work abrading apparatus



Nov. 27, 1951 R. G. HALL ETAL 2,576,737

AUTOMATIC WORK'ABRADING APPARATUS Filed July 10, 1948 9 Sheets-Sheet lINVENTORS l Pol/Ono 0. Ho// Stewart M H/'// QTTOR/VEY Nov. 27', 1951 R.s. HALL ETAL 2,576,787

AUTOMATIC WORK ABRADING APPARATUS Filed July 10, 1 948 9 Shegts-Sheet 2as? as 7 634 IN V EN TORS Pol/and G Ho/f Ste wart M H/// TTOR/VEY Nov.27, 1951 R. G. HALL EIAL 2,576,787

AUTOMATIC WORK ABRADING APPARATUS v Filed July 10, 1948 9 Sheets-Sheet s5 INVENTORS IE 3 "1% m 9 Sheets-Sheet 4 INVENTORS Romy/70 6 Ho'//Stewart MH/fl ATTORNEY rllr brd R. G. HALL ET AL AUTOMATIC WORK ABRADINGAPPARATUS Nov. 27, 1951 Filed July 10, 1948 Nov. 27, 1951 R. G. HALL ETAL AUTOMATIC WORKABRADING APPARATUS Filed July 10, 1948 9 Sheets-Sheet 51 D Fm /@0 FITTORNEY Nov. 27', 1951 R. 5. HALL ETAL 2,576,787

AUTOMATIC WORK ABRADING APPARATUS Filed July 10, 1948 9 Sheets-Sheet 6IN VEN TORS Poflo/no (3. HOW

C BY Stewart M H/I/ FM 41M #1 H T TOHNE Y Nov. 27, 1951 R. ca. HALL EIAL2,576,787

AUTOMATIC WORK ABRADING APPARATUS Filed July 10, 1948 9 Sheets-Sheet 7INVENTORS Refit/m0 6. H0// Stewart M H/// BY HTTORNE) Nov. 27, 1951 R.e. HALL ETAL AUTOMATIC WORK ABRADING APPARATUS Filed July 10, 1948 9Sheets-Sheet 8 INVENTORS FRO/M00 G Ha// BY Stewart M H/'// HTTOFPNEYNov. 27, 1951 R. G. HALL EI'AL AUTOMATIC WORK ABRADING APPARATUS 9Sheets-Sheet 9 Filed July 10, 1948 INVENTORS ECHO/70' G HU/l Stewart MH/'// HTTORNEY Patented Nov. 27, 1951 AUTOMATIC WORK ABRADING APPARATUSRolland G. Hall, Yalesville, Conn., and Stewart M. Hill, Sherrill, N.Y., assignors to R. Wallace & Sons Manufacturing Company, Wallingford,

Cnn., a corporation Application July 10, 1948, Serial No. 38,066

9 Claims. 1

This invention relates to apparatus for finishing opposite surfaces oredges of manufactured articles, and more especially, though notexclusively, to apparatus for trimming and/ or buffing the oppositeedges of table flatware, such as the customarily butt-joined side edgesof knife handles, for instance.

It is the primary aim and object of the present invention to provideapparatus of this type which will perform simultaneously on a largenumber of identical articles, such as knife handles, in such fashionthat the opposite edges of the knife handles are operated on under thecontrol of a master cam which not only prevents excessive abrading ofthese handles, but also preserves their correct contours and evencorrects their contours where they are slightly off.

It is another important object of the present invention to provideapparatus of this type which is fully automatic in its operation and hasoperating cycles of predetermined duration that are started on momentarymanipulation by an operator of a control element of the apparatus.

t is another important object of the present invention to provideapparatus of this type in which during an operating cycle thereof thework to be abraded is first moved from a retracted position intooperative engagement with oppositely spinning abrading or operatingwheels, is then repeatedly reciprocated while remaining in operativeengagement with the operating wheels, and is finally returned toretracted position for removal from the apparatus without interferencefrom the spinning wheels.

It is another important object of the present invention to provideapparatus of this kind which, by a simple manipulation of a controlelement of the apparatus and quick and facile exchange of the operatingwheels thereof, is adaptable either to a trimming operation or to abufiing operation, the latter to include the application of a buffingcompound to the buffing wheels at the beginning of each buiiing cycle ofthe apparatus.

t is another important object of the present invention to provideapparatus of this type with interchangeable work racks so that one rackmay be loaded with a multitude of knife handles to v be operated on,while another loaded rack is in the apparatus and the knife handlesthereon are being operated on.

It is another important object of the present invention to provide inapparatus of this type for movement of the work to be operated on intransverse directions between the fast spinning trimming or buffingwheels, depending on the type 2 of operation to be performed, so as toobtain optimum performance of these wheels on the workduring anoperating cycle of minimum duration.

It is another important object of the present invention to operate thepresent apparatus principally hydraulically for attaining simplicity ofconstruction of the apparatus, and accomplishing its efficient operationwith a minimum number of movable parts and a minimum of wear between theparts.

It is another important object of the present invention to provide thepresent apparatus with controls that render the latter foolproof in itsoperation, and permit instantaneous interruption for any length of timeof an operating cycle of the apparatus by the operator for the purposeof inspecting, or making adjustments on, the work or the operating partsof the apparatus.

The above and other objects, features and advantages of the presentinvention will be more fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. 1 is a front perspective of apparatus embodying the presentinvention;

Fig. 2 is a rear perspective of the apparatus;

Fig. 3 is a front elevation of the apparatus;

Fig. 4 is a side elevation, partly in section, of the apparatus, asviewed in the direction of the arrow 4 in Fig. 3;

Figs. 5 and 6 are vertical sections through the apparatus, takensubstantially on the lines 55 and 66, respectively, of Fig. 3;

Fig. '7 is a fragmentary section through the apparatus, takensubstantially on the line 1-1 of Fig. 6;

Fig. 8 is a fragmentary section taken on the line 8--8 of Fig. 3;

Figs. 9 and 10 are sections taken on the lines 9-9 and Hll 0,respectively, of Fig. 4;

Fig. 11 is an enlarged, fragmentary section through the apparatus, takensubstantially on the line I lll of Fig. 3;

Fig. 12 is a front elevation of a work-rack used in the presentapparatus;

Fig. 13 is a section taken on the line l3-l3 of Fig. 12;

Fig. 14 shows diagrammatically, in side elevation, certain cooperatingparts of the apparatus shown in Fig. 5;

Fig. 15 is a plan view of the parts shown in Fig. 14;

Figs. 16 and 1'7 are views similar to Fig. 14, but

3 showing the parts in difierent operating positions;

Fig. 18 is a wiring diagram of the electrical controls of the presentapparatus; and

Fig. 19 is a hydraulic diagram of certain fluidpressure operated devicesof the present apparatus.

Briefly, the instant apparatus is adapted to perform, by way of example,on the opposite side edges e of hollow knife handles k (Figs. 12 and 13)which are customarily formed of complementary halves that are solderedalong the seam s. In order to render the scams toall intents andpurposes invisible on the finish-ed knife handle, they are subjectedfirst to a trimming operation and then to a buffing operation. In thisconnection, it may be stated in advance that the present apparatus is soconstructed as to be adaptable for trimming operation or forbufiingoperation, or both.

The instant apparatus comprises a base frame 36 which is in the form ofa housing having a front wall 32, side walls 34, and a rear wall 36which leaves an opening 38 in the rear of the frame for ready access tothe interior thereof. The front and rear walls 32 and 36 are lined atthe top with angles 46 (Figs. 5 and 6) on which is mounted in anysuitable manner a platform 42. The side walls 34 of thebase frame 36 mayalso be provided at the top with inwardly extending flanges 44 (Fig. '7)which serve as additional mountings for the platform 42. Mounted in andon the base frame 36 are, as hereinafter described, the operating WheelsA and their respective drives B (Figs. 5, 6 and 7). 50, or otherwisesecured, to the opposite side walls 34 of the base frame 36 are,standards 52, respectively, which are joined at the top by a brace 54 inthe form of a plate that may be connected with the standards 52 byangles 56 (Fig. 2). Mounted on the braced standards 52 are, as here:-inaft-er described, a work carrier C (Figs. 1,3 and 6), carrieroperating devices D (Figs. 1, 2 and 8), controls E for the operatingwheels (Figs. 1 and 4) a buffing compound applicator F (Figs. 1, 3 and11); electrical controls G of apparatus (Figs. 1, 3 and l8),'and ahydraulic control system H (Fig. 19).

Operating wheels A mounted on a shaft 62, and are preferably cementedtogether in their side-by-side relation so as to constitute a fairlyrigid wheel. If the wheels 66 are to be used for trimming purposes,their peripheries are preferably coated with a grinding compound whichlasts for a considerable number of trimming cycles of the apparatus be,-fore recoating is required. If the wheels 66. are to be used for bufiingpurposes, there is applied in the present instance, a bufiing compoundto their peripheries at the start of each buffing cycle of theapparatus.

Journaled in suitable bearing brackets 16 on the base frame 36 are twocountershafts 12 (Figs. 6 and 7), each of which carriesnear its endsarms I4 that extend through transverse slots 16 in the'platform 42 ofthe base frame 30 (Figs. 5 and 7). The arms I4 on each shaft l2,together' with removably mounted caps'lB thereon,

I 7 provide spaced journal bearings for the shaft 62 o'f'an operatingwheel 66, The shafts 12 are Bolted at rocked in opposite directions soas to swing the operating wheels 66, in the course of their per-'formance, to and from each other in a manner and by means hereinafterdescribed. The peripheries of the wheels 66 extend into the interior ofthe base frame 30 through a cutout 4! in the platform 42, said cutouts!being of sufficient width (Fig. 6) to permit the abovementioned swingingmotions of the wheels 66. Since the wheels 66 perform an abradingoperation regardless of whether they are used for trimming orfor'buffing, there is provided underneath these wheels'apan 86 (Figs. 6and 7), which is suitably secured to the; platform 42, and receives allwaste matter dropping from the work and from the wheels 68. The pan hasat the rear of the apparatus an outlet 82 which may, through a suitableconduit (not shown), communicate with any conventional suction devicefor drawing the accumulated waste matter from the pan 80. Suitablyhinged at 84 on the platform 42 are guards 86 over the exposedperipheriesof the wheels 60 (Figs. 1 and 6), these guards serving notonly to keep the operators hands from the wheels 66, but also to directall waste matter from the work and operating wheels into the pan 30provided therefor.

Wheel drives B Two opposed ends of the shafts 62 of the operating wheels66 extend beyond the adjacent sides of the base frame 36 and there carrypulleys 96, respectively (Fig. 3). The pulley Sfion the rear Wheel 66(Figs. 6 and 7) is drivingly connected by belts 92 with a pulley Mon theshaft 96 of an electric motor 98 which issuitably mounted on a bracketIllilthat is, in turn, mounted for swinging movement at I62 in a bearingbracket I64 0n the front wall 32. of thebase frame 30. The bracket I00is provided with an upward extension I66 in which is swivelled the shankI68 of a nut III] with which a spindle H2 is in threaded engagement. Thespindle I I2 has any conventional universal mounting in a. bracket I I3.on the rear wall 36 of the base frame 30, and carries a hand wheel H5.Thus, the tension of the belts 92 may be regulated by turning the handwheel H4 in the proper direction and, in consequence, swinging themotor-carrying bracket I66 on its pivot axis I62. The pulley 96" on thefront wheel 66" is drivingly connected by belts I20 with a pulley I22 onthe shaft I24 of another electric motor I26 which, asshown in Fig. 5, iscarried by a mounting bracket I28, journaled at I36? in. a bearingbracket I32 on the rear'wall36 of the base frame 36. Swivelledin anupward extension I34 of the mounting bracket I28 is the shank. I35 of anut I36 which is in threaded engagement withv a spindle 136- that hasany conventional universal mounting in a bracket l40'on the rear wall 36of the base frame 36 and carries a hand wheel I42, the latter'to bemanipulated for regulating the tension of the belts I20, as will bereadily understood. Thus, the wheels 60 are-individually driven fromtheir respective motors 98 and I26, in opposite directions, and moreparticularly in the direction of the arrows I46 and I48, respectively,in Fig. 6.

Work carrier C Referring now more particularly to Figs. 1 and 3; thework carrier comprises, in the present instance-a verticallyreciprocatory frame I56. and

I54 and I58 and connecting cross bars I58. The brackets I54 and I56 areslidable on vertical guide posts I55 and I51, respectively, which aremounted on the adjacent standards 52, respectively, throughintermediation of mounting brackets I60 (Figs. 1 to 5). Thus, thesliding brackets I54, I56 and the connecting cross bars I58 form asingle unit which is vertically reciprocable on the guide posts I55 andI51.

The oscillatory frame I52 comprises side members I62 and connectingcross bars I64, which together form a single unit. The side members I62are reclined for sliding movement on the cross bars I58 of thereciprocatory frame I50, thus permitting oscillation of the frame I52 onthe other frame I50 transversely of the direction of re ciprocation ofthe latter frame.

Preferably, there are interposed between the slides I54 and I56 and theadjacent brackets I60, respectively, bellows I68 of rubber or the likewhich surround the guide posts I55 and I51, respectively, and contractand expand on reciprocation of the frame I50, as will be readilyunderstood. These bellows I68 protect the guide posts I55 and I51 fromdust and other foreign matter. The length of the guide post I55 betweenthe lateral lugs I of the slide I54 is also protected from dust andother foreign matter by a sleeve I12 which surrounds post I55 and isinterposed between the lugs I10 in the manner best shown in Fig. 3.Those portions of the cross bars I58 of the frame I50 on which the sidemembers I82 of the oscillatory frame I52 oscillate, are preferably alsoprotected from dust and other foreign matter by contractable andexpansible bellows I14 which, as best shown in Fig. 3, are anchored withtheir ends on fixed collars I16 on the cross bars I58 and on similarcollars I18 on the side members I62, respectively.

The present apparatus is also equipped with .1

one or more detachable work racks I80, one of which is shown in Figs. 1and 12. The work rack I88 is in the form of a U-shaped bar havingopposite legs I82 and a connecting yoke I84. The legs I82 of the workrack are provided with elongated slots I86 by means of which the workrack is suspended from headed pins I88 on the lower ends of the sidemembers I62 of the oscillatory frame I52 (Fig. 6). Suitably secured inthe yoke I84 of the work rack I80 are a multiplicity of blades I90 whichserve as holders for the knife handles it to be operated on. Moreparticularly, the knife handles are inserted over the blades I88 (Figs.12 and 13) and are held thereon in upright position (Fig. 13). Whensuspended from the oscillatory frame I52, as described, the work rackI88 is located in the median vertical plane between the wheels 60 asshown in Fig. 6, so that the knife handles is on the work rack will beevenly contacted on opposite sides by the operating wheels 60 onvertical reciprocation of the work rack with the frames I50 and I52.

Operating devices D for work carrier Referring now to Figs. 1, 3 and 6,there is mounted at I92 on the plate 54 between the standards 52 ahydraulic cylinder I94 in which is slidable a double-acting piston I85(Fig. 19) the rod I88 of which is connected at I98 with a bracket 200(Fig. 6) which is carried by the cross bars I58 of the frame I50, andserves to impart the reciprocatory motion of the piston I95 in thework-rack cylinder I94 to the frame I50.

Theprime mover for the oscillation l of the frame 1521s an hydraulicmotor 202 (Figs. 2, 6 and 8) which is carried by a housing 204 that is,in turn, mounted in any suitable manner on the plate 54 between thestandards 52. The hydraumotor 202 is as of a well known type andrequires no detailed disclosure. For the present purpose, it issufiicient to understand that the drive shaft 206 of the motor 282 turnsin one direction on the passage of a liquid under pressure through the.motor. The housing 204 is closed at its open front by a cover 208, andhouses a gear 2 I 0 (Fig. 8) which is mounted on the motor shaft 203 andis in permanent mesh with another gear 2I2 on a shaft 2I4. Shaft 2I4 isjournaled in the housing 204 and cover 208, and carries externally ofthe housing 204 a disk 2I6 having a crank pin 2I8 which is received in avertical groove 220 in the rear of the side member I82 of theoscillatory frame I52. Thus, the frame I52 and, hence, also the workrack I88 thereon will, on operation of the hydraulic motor 202, beoscillated on the frame I58, and such oscillation of the frame I52 maytake place uninterruptedly during reciprocation of the other frame I50.

Controls E for operating wheels Referring now more particularly to Figs.1, 3 and 4, the rock shafts 12 of the operating wheels 60 haveextensions 232 beyond one side of the base frame 30 and there carry arms234, respectively, which are provided at adjacent ends with followers236, respectively, adapted to cooperate with master cams 238,respectively. The opposite ends of the arms 234 are pivotally connectedat 240 with an extension 242 on a cylinder 244 and a piston rod 246,respectively. Rod 246 is carried by a double-acting piston in thecylinder 244, the opposite ends of which communicate with a source ofliquid under pressure through conduits 248 and 250, respectively. Whenliquid under pressure is admitted through conduit 250 into theright-hand end of the cylinder 244, as viewed in Fig. 4, the pistontherein is forced to the left, with the result that the lower ends ofthe arms 234 are forced apart and the followers 236 on the other ends ofthe arms 234 are forced into engagement with their respective mastercams 238. Conversely, the followers 238 on the arms 234 are disengagedfrom their respective master cams 238 when liquid under pressure isadmitted through conduit 248.

The master cams 238 are accurately positioned on dowel pins 25I onopposite slides 252 and 254, respectively, and are held thereon byscrews 258 (Figs. 4 and 10). The slides 252 and 254 are guided formovement to and from each other in a horizontal dovetail groove 258 in aslide 258 (Fig. 10) which is, in turn, guided for vertical movement in adovetail groove 280 in the sliding bracket I54 of the reciprocatingframe I58 (Figs. 1, 3, 4 and 9). The cam-carrying slides 252 and 254 arein threaded engagement with oppositely threaded lengths 252 and 284,respectively, of a spindle 266 which is suitably journaled in forwardlyprojecting lugs 288 of the vertical slide 258 and carries at one end ahand wheel 21%) with which to turn the spindle 266 and thereby adjustthe spacing of the master cams 238 in accordance with the width of theknife handles to be operated on by the operating wheels 60. The verticalslide 258 is in threaded engagement with a spindle 212 which is heldaxially immovable in a projecting lug 214 on the adjacent bracket I54and carries thereabove a hand wheel 216 with which to turn the spindle212 and there-.

7 by adjust. the-master cams 238 incorrect vertical position.

The active faces. 280 of the. mastercams 238 aremachined so thatintermediate lengths there'- of, corresponding to the length of a knife.handle to. be operated on by the wheels. 63, has; the correct contour ofthis knife handle, and the'master cams. 238 are so adjusted, throughmanipulation of the hand wheels 2') and 276, thatthecorrect contourportions of these: master cams cooperate with the followers 236 on thearms 234 when the corresponding contour portions of the knife handles onthe mounted work. rack I80 are in operative engagement with the wheels60.. Thus, the wheels: 60, be they trimming or buffing wheels, are, onreciprocation of the work between the wheel fill, positively moved toand from each other in such manner that their: peripheries follow: thecorrect contour'of the work, thereby preventing excessive abrading ofthe knife handles, and even correcting the contours of the latter whereslight- Bufiing compound applicator F Referring now to Figs. 1, 3 and11, there is shown a buffing compound applicator 290 which, at thebeginning of each bufiing cycle only of the apparatus, travelsalong theoperating wheels 60, first in onedirection and then in the oppositedirection, and discharges the compound in relatively liquous form on theadjacent peripheries of the wheels 66. The applicator 293is mounted at292 on a cross head 294 which is slidable axially of the wheels 63 onrods 296'thatare mounted with their ends inopposite brackets 298 and 300on the standards 52, respectively (see also Fig. '7). Journaled with itsends in the bracket 300' and in a cover 302 on the opposite. bracket298, respectively, is a spindle 30 3 which is in threaded engagementwith a bushing306 in the cross head 29 so that, on rotation of thespindle 304 in opposite directions, the cross head 234' is moved inopposite directions on the rods 296. One end of the spindle 394 (Fig. 7)is coupled at 368 to the drive shaft Bill of a reversable hydraulicmotor 312 which is'suitablyv mounted on the outside of the adjacent.standard 52; The motor is of. a conventional type which reverses thedirection of rotation of its drive shaft on reversing the fiow of aliquid under pressure through the motor.

The compound applicator 290 comprises, in the present instance, two'sprayers 222'which;have nozzles 224 through which bufiing compound isdirected against the peripheries of the operating wheels 69,respectively (Fig. 11). The sprayers 222 are of a conventional andwellknown type and do not require a detailed disclosure. Ea'ch.

sprayer contains a bufiing compoundm liquous form which, on the flow ofcompressed air through a Venturi passage in the sprayer, is forced: fromthe latter through the nozzles-224 thereof. Com pressed air is conductedfrom an air valve 223 to the sprayers 222 through a flexible hose.connection 225 and tubes- 225' and 227, respectively. The air valve223', which is mounted on a bracket 228 on one of. the standards 52(Figs. 2 and 7), is, through a conduit (not shown), in permanentcommunication with a source of compressed air. The air valve 223 has acontrol-element 229which is turnable'into positions toopen and close thevalve.

head 294' for opening andclosing the valve; -As

previously 'stated, the compound applicator 290 The control element 229of :the air valve .223 is provided with a laterally projecting finger-230. which cooperates with a pin 23| on the cross;

8 is,. at the beginning of each buffing; cycle? of the apparatus, moved;from the. home: position. shown inFig; 3,.first to. thezleftand thenback into home position, the'work rack [80: in theapparatus being thenin its uppermost positioniso. as not to interfere with the describedtravel of the compound applicator. Immediately after the compoundapplicator 29!) starts'to move from home position, the .pin 231- on thecross head 294 engages;

the finger 23B and turns the control element 229 of the air valve. 223:into open position in which compressed air passesv through the latter tothe sprayers, 222' for therforced discharge of buffing compoundtherefrom. 'The control element 229 of the air valve 223 is, on beingturned into open position by the pin'23l as described, backed up againsta spring (not shown) in the'valve which, after the passage of the crosshead 29 1, will return the control element 229- into a position in whichthe air valve 223 is still open and the finger 230 is in the path ofmovement of the pin 23| on the following return movement of the crosshead 294 and compound applicator 29ll-into home position. Thus,-. thepin 23I on the cross head 294 will turn the control element 229 intovalve-closing position shortly before the cross head 294- and compoundapplicator 2% return to home position. The control element 229 is, onbeing turned into valve-closing position by the pin 23l as described,backed up against a spring (not shown) in the valvewhich, after passageof the cross head 294, turns the control element 229 into a position inwhich the air valve 223 is still closed and the finger 239 is in thepath of movement of the pin 23! for the next performance of the compoundapplicator 290 at the start of the next buffing cycle of the apparatus.

Electrical controls G of apparatus The heretofore mentionedhydraulically operated devices H34, 202, 244, and 312 require for theiroperation a liquid, such as oil, which is put under pressure in a mannerhereinafter described by a pump 320 (Fig. 19) that is driven.

is on its circuitous path through the apparatus. effectively cooled soasto preserve its maximum operating efficiency. Thus, the presentapparatus has four electric motors of which two drive the operatingwheels 30, one drives the pump 323 and another operates the fan which isassociated with the oil-cooling unit 326. The apparatusfurther'comprises solenoid-operated valves 330' and 332 (Fig. 19) whichare mounted on the plate 54 betweenthe standards 52, and arepreferably'enclosed in covers 334, respectively (Figs. 1 and 3'). Thesolenoid valve 330 is one of several controls for the admission of oilunder pressure to, or its interception from, the Work-rack cylinder I94,while the other solenoid valve 332 controls the admission of oil underpressure in opposite directions to the hydraulic motor 3| 2 which drivesthe. feed spindle 304 for the compound applicator 29G. Solenoid valve330 haswindings 336 and 338* (Fig. 18) and the other solenoid valve 332has windings 340 and 342.

' Reference is now had to the Wiring diagram in Fig. 18 which disclosesthe electrical controls for the abovementionedelectric motors 98, I23,322 and 324, as well as for thezsolenoid coils 335, 338- and 340,. 342.These controls-include. aflStart switch 344, a Stop switch 346, aPump-wheel switch 348, a Raise-stop-auto switch 358, and a timer 352,all as shown in Figs. 1, 3 and 18.

The sole current source used in the present apparatus is a 3-phasecurrent represented in the wiring diagram by the lines LI, L2 and L3. Tostart the apparatus, the operator throws switch 348 into the Pumpposition in order to connect the pump motor 322 and fan motor 324 withthe electric power source and build up oil under pressure in the variousoil lines to be described in the apparatus, before the wheel motors 98and I26 are permitted to run and before the work is permitted to comeinto operative engagement with the wheels 69. switch 348 into the Pumpposition as described, there is closed a starting circuit of a holdingcoil 368 which is part of a conventional magnetic starter switch 362.Coil 368 will, on energization, close all normally open pairs ofcontacts 364 of the starter switch 362. The starting circuit of theholding coil 368 of the starter switch comprises line LI, a lead 366,the normally closed stop switch 346, a lead 368, the

bridged contacts a and b of switch 348, leads 318 and 312 with thenormally closed switch 314 in the latter lead, holding coil 368, lead315 with the interposed, normally closed switch 316, and line L2. Withthe contact pairs 364 in the starter switch 362 closed in consequence ofthe energization of the holding coil 368, the lines LI, L2 and L3 areconnected with the pump motor 322 through the starter switch 362 in aself-evident manner. On closure of the magnetic starter switch 362 asdescribed, the primary 388 of a.

LI to L3 may be used for the pump motor 322 and also for the wheelmotors 98 and I26, there is available at the secondary 388 of thetransformer current of lower voltage which is suitable for the fan motor324 and the solenoid windings 336, 338 and 348, 342.

The operator next throws switch 348 into the I Wheel position in whichthe contacts and d thereof are bridged by the movable switch blade 334.In doing so, the above described starting circuit of'the holding coil368 of the starter switch 362 is interrupted at the contacts a and b ofswitch 348, but a holding circuit of the coil 368 has also been closedimmediately on closing the starting circuit thereof. This holdingcircuit of the coil 368 comprises line LI, lead 366, stop switch 346,lead 368, a lead 538, the then magnetically closed switch 364', lead 312with the normally closed switch 314, coil 368, lead 315 with theinterposed normally closed switch 316 and line L2. With the switch 348in Wheel position, the circuit of a holding coil 396 of another magneticswitch 298 is closed, whereby all normally open pairs of contacts 488 ofthe latter switch are closed. The circuit of the holding coil 396comprises line LI, switch 332, leads 482 and;

484, the then bridged contacts 0 and d of switch 348, leads 486 and 488with the normally closed switch 4!!) in the latter lead, holding coil396, lead 4I2 with the interposed, normally closed switch 414, lead 4I6,starter switch 362 and line By shifting the L2. Thus, on closure of thedescribed circuit of the holding coil 396 of the magnetic switch 398, inconsequence of the shift of switch 348 into the Wheel position, thewheel motors 98 and I26 are connected in a self-evident manner with thepower lines LI to L3 through the closed magnetic switches 362 and 398.It follows from the preceding that the wheel motors 98 and I26 mayoperate only after the pump and fan motors 322 and 324 operate, for thecircuits of the latter motors are closed on closure of the magneticswitch 362, while the circuits of the former motors are closed onclosure of both magnetic witches 362 and 398 only, and switch 398 can beclosed only after switch 362 is closed.

At this stage in an initial operating cycle of the apparatus, the pumpmotor 322, fan motor 324 and the wheel motors 98 and I26 are operating,but the loaded wori: rack I88 in the apparatus is still in the raisedposition shown in Fig. 6. Assuming that the apparatus is to perform abufiing operation, a manual switch 428 has then previously been closedso that the compound applicator may next perform its designated functionof spraying the peripheries of the operating wheels 68 with buffingcompound. Hence, with the switch 428 closed, manual operation of thestart switch 344 at this time will start a performance of the compoundapplicator 298. Depression for a brief period of time of the startswitch 344 into position in which the same bridges the contacts a and bthereof results in closure of a starting circuit of the solenoid winding348, which circuit comprises one side a: of the secondary 388 of thetransformer, a lead 424, a contact 426 of the timer 352, a lead 428 withits intermediate connection 429 with the solenoid windings 336 and 338,solenoid winding 348, leads 438 and 432, the momentarily bridgedcontacts a and b of the start switch 344, a lead 434, the closed switch428, a lead 436, and the other side 1 of the secondary 388 of thetransformer. Simultaneously with the closure of this starting circuit ofthe solenoid coil 348, there is also closed a starting circuit for arelay 438, the latter circuit comprising side a: of the secondary 388 ofthe transformer, lead 424, contact 426 of timer 352, a lead 448, relay438, a lead 442, a

normally closed snap switch 444, a lead 446, leads 438 and 432, themomentarily bridged contacts a and b of the start switch 344, lead 434,closed switch 428, lead 436, and the other side y of the secondary 388of the transformer.

As previously mentioned, the compound applicator 298 assumes, in thehome or idle position of the apparatus, the position shown in Figs. 1and 3, in which a pin 458 on'the cross head 294 (Fig. 7) holds themovable blade 452 of a snap switch 454 (Fig. 18) in engagement with thecontact 456 thereof against the normal tendency of the blade 452 tospring into engagement with the other contact 458 thereof. The switch454 is conveniently mounted on one of the standards 52 (Figs. 2 and '7)and is accessible to the pin 458 on the cross head 294 through anopening (not shown) in said standard. As soon as the abovedescribedstarting circuit of the solenoid winding 348 is closed, the compoundapplicator will, in a manner hereinafter described, move immediately tothe left as viewed in Figs. 1 and 3, i. e. away from the snap switch454, so that the blade 452 thereof will spring from the full-line position into the dotted-line position shown in Fig. 18, while the operatorstill holds the start switch 344 depressed. The described startingcircuit of I 1 l theirelay438 is interrupted when the operator releasesthe start switch 344,'bu t1the blade 452 of the snap switch 454 has. inthe meantime assumed the dotted-line position inFig. 1:8 in which;itxconnectsthe contacts 458 and460 which are in-a holding circuit ofthe relay 438. This holding .nircuiticomprises side as of the secondary388 of thetransformer, lead 424, contact 425 of timer e315-2,.lead 440,relay 43 8, lead 442, switch, 444,,leads 4'45 and 43!), thenormallydisengaged contacts :464 and 468 of a switch 451 which has alsonormallyopen contacts412 and 414, and of which theJformer contacts arenow engaged, and the latter contacts disengaged, due to the energizationof relay 438 on previous closure of the startiing circuit thereof.allead 468, the'then bridged contacts'458 and 468 of switch 454, a lead410, and the; other side y of the secondary 388 of the transformer.Simultaneously with the described closure of the holding circuit of therelay 438, there is "also closed a holding circuit. of the sole- :noidwinding 340, the latter circuit comprising side a: of the secondary 388of the transformer, lead-424, contact 4280f timer 852, lead 428qwi'th--itsiintermediate connection 429 with thesolenoid winding-e338 and338,solenoid winding 348, lead 438, the-engaged contacts 454 and 484 ofswitch 48]., lead 4.68, switch454, lead 430, and the other side yet the;secondary 388 of the transformer. Thus; the holding circuit of thesolenoidrwinding 348 'is closed while the compound applicator 288travels initially along the wheels '68 to the left-as shown-in Figs. 1and 3, :or to the :right'asviewed gin Fig;;2. Toward the end of thedescribed-initial :travel of the compound applicator 298a pin 4.8.0 onthe cross head 294 (Figs. 1, 2 and .7) engages :and opens thesnap switch444, which is mounted on the outside of one of the standards 52 and isaccessible through an opening 482 in the latter i (Figs. 2 and 6). Whenswitch 444 is thusopened :at the end of the initial travel of thecompound applicator 298, the above-described holding circuits of therelay 438 and solenoid winding '34!) are opened and the circuit of thesolenoid winding 342 is simultaneously closed for the return travel ofthe compound applicator 280 into home position, as hereinafterdescribed. This latter circuit comprises side a: of the secondary 388 ofthe transformer, lead 424, contact 426 of timer 352, lead 428 with itsintermediate connection 429 with the solenoid windings 336 and 338,solenoid winding 342, a lead 490. the then normally 12 a switch 35litothe Auto position, thereby con- .ditioning-the circuit of the winding 33.5 of, the solenoid valve 384 forclosure immediately when the returningcompound applicator shifts switch 454 into the afull-line: positionshown in Fig. 18. The circuit .of. the solenoid winding 338 comprisesside -x-of the secondary 388 of the trans- .former, lead 424, contact424 of the timer 352, lead 423,, solenoid winding 336, a lead 484, thethen connected contacts, 496 and 498 of the timer 352, a lead 508, acontaoti5il2 of the time 352, a lead 584, the then bridged contacts 0'and d of switch 358,-a lead 588, the-normally bridged contacts a and'b"of switch 344, a lead 548, the then bridged contacts 456 and 458 of.switch 454, leadAid,,and'thebther sidey of the secondary 388- of thetransformer. Closureof this latter circuit causes a shift of thesolenoid valve 3.38 from a neutral position to be described into thefull-line position shown in Fig. 19, in which the same is conditionedfor power reciprocation of the pistonv [95 in the work-rack cylinder m4in 'amannerrhereinafter described. The subsequent reversal at the end of:each stroke of the piston l95-in the work rack. cylinder I94 isunderthe control of a pilot valve 540 which is operated :by'the reciprocatingframe I in a manner hereinafter described; The timer 352 may be presetto iany predetermined' time period, within limits, which is chosen for abufling cycle. A detailed disclosure of the timer 352 is not deemedessential for an understanding of the present invention, and .is, hence,omitted, particularly since this timer :is of a conventional type. andits con- ;struction forms .no spart-of the present invention. ,However,if the timer isset for a bufiing cycle and, hence, for a longer durationof the cycle, the contacts 49.6 and 498 thereof will be disconnected,and will, in a manner conventional for this .timer, be connected onlyafter the compound applicator 298 has in the course of its per-;formance ina bufiing cycle, moved fromhome position. In this way,closure of the solenoid winding 33B and, hence reciprocation of the workrack piston 195, are prevented at the beginning 0f .a bufling cycleof'the apparatus before the compound applicator moves from homeposition. If the apparatus is conditioned for trimming operation; .thetimer is, due to the cut-out of the operation of the compoundapplicator, set for a shorter time period, at which setting the contacts498 and 498 .will be connected for immediate engaged contacts 412 and 414 of switch 461,,lead

488, "the then bridged contacts 458 and 458 of switch 454, lead 410, andthe other side 3/ of the secondary 388 of the transformer. Energizationof the solenoid winding 342 will, as hereinafter more fully described,result in return travel of the compound applicator 290 into homeposition. When the compound applicator reaches home position the pin 458on the cross head 294 (Fig. *7) returns blade 452 of switch 454 into thefull line position shown in Fig. 18, opening thereby the-circuit of thesolenoid winding 342, with the result that the com ound applicator comesto a 'stop in home'position. The peripheries of the turning wheels 88having now been sprayed with bufiing compound, the work rack I84,which-is normally in its uppermost position (Fig. 6) starts to descendimmediately when the compound ap- *plicator reaches home position andactuates switch 454 in the described manner, i. e., forces switch blade452 into the full-line position shown in Fig. 18. Prior to this stage inan operating cycle' of the apparatus, the operator has shifted closureof the solenoid winding 336 and according reciprocation of the work rackpiston I at the beginning of each trimming cycle. Whether .the. timer isset for bumng performance .or for trimming performance of the apparatus,the timer will, at the end of each. cycle be returned toits presetposition for. the next cycle. At the end of the predetermined timeperiod for which the timer 3'52 isset, the contacts 495 and 488 of thetimer are disconnected and the contacts 482 .and 51;.6'thereof areconnected, opening thereby the above-described circuit of the solenoidwinding 336 and simultaneously closing the circuit of "the :solenoidwinding 338 of the solenoid valve 338. This latter circuit comprisesside' 0: of the secondary 388 of the transformer, lead 424, contact 426of timer 352, lead 428, solenoid winding 338, a lead 520, the thenconnected contacts Eit .and 498 of the timer 352, lead 548, contact 582.of the timer, lead 584, the then bridged contacts .0, d of switch 35!),lead 586, the normally bridged contacts a", b" of switch 344, lead 558,the then .bridged contacts 456 .and 468 of switch 454, lead v of theapparatus.

416, and the other side 1; of the secondary 388 of the transformer.Closure of the circuit of the solenoid winding 338 will result in ascentof the work rack I86 to its uppermost position in which it will remain,without being oscillated, until the operator starts the next operatingcycle by depressing the start switch 344, provided the stop switch 346has not been opened in the meantime by the operator for a purposehereinafter described.

The switches 348 and 356 having been left in their respective Wheel andAuto positions, and the work rack I86 having been removed from theapparatus, and either reloaded and returned in the apparatus, orreplaced by another loaded rack, the operator need merely depress thestart switch 344 in order to start another bufiing cycle If the presentapparatus is to be used for trimming the side edges of knife handles,the bufiing wheels 66 are replaced by trimming wheels, though for largeproduction it is preferable to use one or more apparatus permanently fortrimming purposes, and one or more apparatus for bufiing purposes. Aspreviously mentioned, the compound applicator is not used when theapparatus is used for trimming purposes. In that event, the compoundapplicator 296 is rendered inoperative by opening the manual switch 426(Fig. 18). With the switch 426 open, the operator may start the trimmingcycle by depressing the start switch 344, after first shifting switch348 into the Pump position and then intoWheel position, and alsoshifting switch 356 into the Auto position. The operating cycle thatwill then take place is in all respects like the above-described initialbuffing cycle, except that the solenoid windings 346 and 342 will not beenergized due to the opening of the switch 426. By failing to energizethe solenoid windings 346 and 342, the solenoid valve 332 willthroughout the cycle remain in a neutral position to be described, withthe result that the compound applicator 296 will remain in its homeposition throughout the cycle and the solenoid winding 336 is energizedon depression of the start switch 344, causing immediate reciprocationof the work in the apparatus.

Once the apparatus has been started and the switches 348 and 366 have,in the course of the initial operating cycle, been shifted to theirrespective Wheel and Auto positions, as described, and are left in thesepositions, repeat cycles may be started by merely depressing each timethe start switch 344. Repeat cycles differ from an initial cycle in thatneither operation of the pump 326 nor rotation of the operating wheels66 need be started at the beginning of veach repeat cycle, for the pumpcontinues to operate and the wheels continue to rotate duringintermittent stops of the apparatus between successive repeat cycles.This is due to the fact that the circuit of the pump motor 322 is closedas long as the magnetic starter switch 362 is closed, and the latterremains closed until the stop switch 346 is depressed, this by virtue ofthe fact that switch 346 affords the only means with which to interruptthe previously described holding circuit of the holding coil 366 of thestarter switch 362. operating wheels 66 during intermittent stops of theapparatus between successive repeat cycles is due to the fact that thecircuit of the wheel motors 88 and I26 are closed as long as the.starter switch 362 and magnetic switch 398 are Continued rotation ofthe closed, and these motor circuits may be interrupted only bydepressing the stop switch 346 or by shifting switch 348 from Wheelposition. The apparatus may be brought to a'full stop only on depressionof the stop switch 346, which results in de-energization of the holdingcoil 366 of the starter switch 362 and corresponding opening of thelatter. Opening of the starter switch 362 interrupts not only thecircuit of the pump motor 322, but also the circuit of the holding coil396 of the magnetic switch 368, resulting in interruption of thecircuits of the wheel motors 68 and I26. The circuits of the remainingelectrical devices of the apparatus are then also interrupted by virtueof the fact that depression of the stop switch 346 results in opening ofthe starter switch 362 and, hence, in interruption of the circuit of theprimary 366 of the transformer 382. Thus, the instant apparatus may bestopped immediately and at any time on mere momentary depression of thestop switch 346, as will be readily understood.

As previously mentioned and as further explained hereinafter, theenergized winding 336 of the solenoid valve 336 efiects operation of thepiston in the work rack cylinder E64 and of the work-oscillating motor262. However, when both windings 336 and 338 of the solenoid valve 336are de-energized, the latter assumes a neutral position to be describedin which the piston in the work rack cylinder I64 is retained in itsuppermost position and the work-oscillating motor 262 is hydraulicallylocked, with the result that the work rack I86 in the apparatus neither.reciprocates nor oscillates. Hence, if switch 356 is, at any timeduring an operating cycle of the apparatus, switch from Auto position toStop position, solenoid valve 336 will immediately shift into itsneutral position, with the result that the work rack I86 will be broughtto an immediate stop in the same position which it assumes at the timeswitch 356 is thus shifted into Stop position. This is highly expedientwhere the operator detects in the course of an operating cycle of theapparatus any condition which may be, or threatens to be, harmful to thework or to the operating parts of the apparatus.

The work rack I66 may, during an interruption in an operating cycle, beraised to its uppermost position and there held for any length of time,by shifting switch 356 into the Raise position and thereby closinganother circuit of the solenoid winding 338, causing movement of thepiston in the work-rack cylinder I94 into its uppermost position, aspreviously described. The latter circuit of the solenoid winding 338 is,in the Raise position of switch 356, closed by way of side as of thesecondary 368 of the transformer, lead 424, contact 426 of the timer352, lead 428, solenoid winding 338, lead 526, a lead 546, the thenbridged contacts 0" and d" of switch 356, a lead 542, lead 566, switch344, lead 568, the bridged contacts 456 and 466 of switch 454, lead 476,and the other side y of the secondary 388 of the transformer.

Hydraulic control system H Assuming that the apparatus is to perform abuifing cycle and has been started as described hereinbefore, thepreviously described electrical controls will, due to the energizationof the solenoid winding 346, cause a shift of the solenoid valve 332from a neutral position to be described into the full-line positionshown in Fig. 19.

When the solenoid valve 3.32 assumes .this fullline position, oil underpressure will flow through the reversible hydraulic motor 3I2 in onedirection in which to causemovement .of the compound applicator .293 inthe initial direction alongthe peripheries of the operating wheels 55..Oil under pressure will then be forced from the pump 323 in an oilreservoir 559 through conduits 555 and 552 and a preferably interposedpressure-regulating. needle valve 554 to and through the solenoid valve332, thence through a conduit 556 to the hydraulic motor 3I2 from wherethe oil is returned to the reservoir 560 by way of conduit 562,.solenoidvalve 332, conduit 55% and conduit 556 with the interposed cooling unit326. Oil under pressure will thus flow through the motor 312 .until thecompound applicator 233 reaches the end of its initial travel and opensthe snap switch 444, closing thereby the circuit of the solenoid winding342 and ac cordingly effecting a shift of the solenoid valve 332 fromthe full-line position into the dot-anddash line position shown in Fig.19. In thus shifting the solenoid valve 332, oil under pressure in'theconduits 555 and 552 will then pass through' the solenoid valve 332 andthrough conduit 5 32 into the motor 3I2 in a direction opposite to theprevious flow of the oil therethrough, the oil then being returned fromthe motor 3I2 to the oil reservoir 553 through conduit 555, solenoidvalve 332 and conduits 56!- and 555. When oil under pressure flows inthis fashion through the hydraulic motor 3I2, the latter causes returnmovement of the compound applicator 290 into its home position.

As soon as the compound applicator 295 reaches home position, thecircuit of the winding 342 of the solenoid valve 332 is interrupted andthe latter returns to its neutral position in which the motor 3I2 ishydraulically locked as hereinafter described. The circuit of thewinding 335 of the solenoid valve 330 is closed simultaneously with theopening of the circuit of the solenoid winding 342, causing thereby ashift of the solenoid valve 336 from a neutral position to be describedinto the full-line position shown in Fig. 19, in which it providescommunication between the conduits 550 and 568, that carry oil underpressure from the pump 325, and a conduit 5'!!! which leads to one endof a control valve 512 in which the admitted oil forces the slidingvalve 514 into the full-line end position shown in Fig. 19, against thetendency of a spring 516 to move the valve 5'54 into the opposite endposition. When the valve 514 is shifted into this full-line position,oil under pressure from the pump 323 is immediately admitted to the topend of the work rack cylinder I94 by way of conduit 555, a conduit 585,a flow control valve 582, conduits 58 i and 586, a control valve 588(assuming at this time full-line position in Fig. 19 for down stroke ofwork rack piston 895 as hereinafter described), conduit 595, controlvalve 512, and conduit 592. Oil under pressure is at the same timeadmitted to the lower end of the work rack cylinder I94 by way ofconduit 584 and a preferably interposed pressure control valve 594.Inasmuch as the exposed cross-sectional area of the piston I 95 in thework-rack cylinder I94 is larger at the top than at the bottom thereof,it stands to reason that the total pressure of the oil against the topface 598 of the piston I 95 exceeds the total pressure of the oilagainst the bottom face 680 thereof, with theresult that the pison E95descends and carries the work on the rack I180 between the operatingcylinderl34 is, during the :descent. of the piston I35 therein,by-passed to the top end of the cylinder by way of conduit 584 andinterposed valve 594, conduit 5'85, valve 588, conduit 533, valve 512and conduit 592.

Simultaneously with the start of the work reciprocation, oil underpressure is also permitted to flow from the pump 325 through theworkoscillating motor 232 by way of the the conduits 553 and 589, aconduit 652, a flow control valve 604, a conduit 605, and the motor.232, thence through conduits B58 and (H3, solenoid valve 33!], andconduits 3I2, 6I4 and 565 to the oil reservoir 560. Thus, the work rackE83 starts to oscillate at the same time it starts to descend on itsfirst work stroke. Simultaneously with the shift of the solenoid valve336 into the full-line position shown in Fig. 19, oil under pressurefrom the pump is also admitted to the active side of the wheel pressurecylinder 244. by way of conduit 559, a conduit 52!], a flow controlvalve 622, a conduit 524, a pressure control valve 626, and the flexiblehose connection 250. The oil in the opposite side of the same cylinder244is then permitted to return to the oil reservoir 555 by way of theflexible hose connection 248, conduit 5H2, solenoidvalve 330, andconduits (H2, (H4 and 555. Thus, on energization of the winding 336 ineach operating cycle of the apparatus, and according shift of thesolenoid valve 339 into the full-line position shown in Fig. 19, thecylinders I94 and 244 and the hydraulic motor 202 simultaneously receiveoil under pressure, with the result that the workrack piston I95 willdescend for the first time in a cycle, the cylinder 244 and pistontherein will bring the operating wheels 65 under the control of themaster cams 2-38, and the hydraulic motor 232 will oscillate the work.

Suitably mounted on vertically adjustable brackets 632 and 533 on theslide I56 of the reciprocatory frame I58 (Fig. 5) are two blocks 634,respectively, having projecting lugs 536 and 538, respectively, whichare adapted to operate the previously mentioned pilot valve 645 (seealso Figs. 14 to 17). The brackets 632 and 833 are slidable in adove-tail groove'635 in the slide i55 (Fig. 5) and are in threadedengagement with axially immovable spindles 63! and 639, respec tively,on the slide I 56, said spindles 531 and 639 having knobs 5M and 643,respectively, with which to turn said spindles and thereby adjust thevertical position of the respective brackets 832 and 633. The pilotvalve 543 comprises a casing '642 (Fig. 19) and a rotary valve element644 therein. The valve element 542 extends to the outside of the valvecasing 553 and there carries a valve actuator 646 having angularlyspaced fingers 648 and 555 which are also spaced horizontally from eachother as shown in Fig. 15. The finger 648 of the valve actuator 546 isin operative alignment with the lower lug 538, while the other finger653 of the valve actuator is in operative alignment with the upper lug535. As previously mentioned, the pilot valve 640 is adapted to controlthe flow of oil to and from the top end of the work-rack cylinder 49% soas to reverse the piston I95 therein at the end of each down or upstrokethereof, and this control is operative throughout the. predeterminedtime period which the preset timer 352 allows for the reciprocation ofthe work in an operating cycle of the apparatus. The verticaladjustability of the lugs 63B and 638 in the apparatus also affords aconvenient meansnotonly to regulate the stroke 1.7 of the piston I95 inthe work-rack cylinder I94 for the reciprocation of the Work, but alsoto confine the reciprocation of the piston I95 to different regionswithin the work-rack cylinder I94. Thus, by properly adjusting the lugs636 and 638, the work will, after its initial descent from uppermostposition, be reciprocated through partial strokes of such length thatthe work will remain in operative engagement with the operating wheels60 throughout its reciprocation, and will at the end of itspredetermined cycle of reciprocation be raised to its uppermost positionin which it is out of operative engagement with the wheels 60 and may beremoved from the apparatus. Also, the described adjustability of thelugs 636 and 638 adapts the apparatus for trimming or buifing knifehandles of different length, as will be readily understood.

The angular position of the valve actuator 646 and, hence, of the rotaryelement 644 in the pilot valve 640 depends solely on the precedingdownward or upward stroke of the reciprocatory frame I50. Thus, when thework-carrying frame I59 descends, the upper lug 636 thereon will, nearthe lower limit of the down stroke of said frame as determined by theadjustment of lug 636, engage the finger 650 of the valve actuator 646and turn the latter from the position shown in Fig. 14 into that shownin Fig. 15, in which finger 650 is out of the path of the lug 636, andthe other finger 648 is in the path of the other lug 638 on thefollowing upstroke of the frame I50. The lug 638 will engage finger 648of the valve actuator 646, and turn the latter back to the positionshown in Fig. 17, when the work-carrying frame I50 is near the upperlimit of its following partial upstroke as determined by the adjustmentof the lug 638. In the position of the pilot valve 640- as shown inFigs. 14, 17 and 19, the same provides communication between the pump320 and the left hand end of valve 588 (Fig. 19) by Way of conduit 550,a passage 660 in-the valve element 644 and a conduit 662. The right handend of valve 588 is then exhausted by way of conduit 664, anotherpassage 66I through the rotary element 644 in the pilot valve 640, aconduit 6'10, and the conduits GM and 566. In consequence of thedescribed admittance of oil under pressure to the valves 588, the latterassumes the full-line position shown in Fig. 19, in which oil underpressure is admitted to the top end of the work-rack cylinder I94, aspreviously described. Hence, the work-rack piston I95 will, in anoperating cycle of the apparatus, descend after each partial upstrokethereof, every time the pilot valve 640 is shifted into the positionshown in Figs. 14 and 19, except when the latter is thus shifted for thelast time in each operating cycle, as will become obvious hereinafter.When the lug 636 shifts the pilot valve 640 into the position shown inFig. 16 on each descent of the work-carrying frame I50, the valveelement 644 of the pilot valve will intercept communication between theconduits 550 and 662, and instead provide communication between conduit550 and another conduit 664 which leads to the right hand end of thevalve 588 as viewed in Fig. 19. Admittance of oil under pressure, to theright hand end of the valve 588 results in a shift of the valve element666 therein from the full-line position into the dotand-dash lineposition. The left hand end of the valve 588 is then exhausted by way ofconduit 662, passage 66I in the rotary element 644 of the pilot valve640, and conduits 610, 6I4 and 5.6.5..- ..Thevalve element 666 of valve588 now being in the dot-and-dash line position in Fig. 19, the samepermits the exhaust of the top end of the work-rack cylinder I94,resulting in an upstroke of the piston I therein because the lower endof the cylinder remains SubJeCted. to oil under pressure. The upper endof the work-rack cylinder I94 is then exhausted by way of conduit 592,valve 5W, conduit 590, valve 588, and conduit 566. When the ascendingframe approaches the adjusted upper limit of its partial stroke, the lug658 engages the aligned finger 648 of the valve actuator 646 and turnsthe pilot valve 640 back to the position shown in Figs. 14 and I9,resulting in the next descent of the work. The work-rack piston W5, and,hence, the frames E56 and I52 as well as the work rack I80, are thusreciprocated until the timer 352 terminates the operating cycle of theapparatus by effecting closure of the circuit 01 the Winding 338 of thesolenoid valve 338. When this occurs, the solenoid valve 338 is shiftedinto the dot-and-dash line position shown in Fig. 19, in which 011 underpressure in the conduit 568 is admitted through the valve 336 and theconduits 6lu and 608 to the work-oscillating motor 202, therebyimmediately locking the latter hydraulically. Oil under pres sure in theconduit 61%] is then also admitted through the hose connection 248 tothe wheel pressure cylinder 244 for effecting separation of theoperating wheels 66 and according disengagement of the followers on thearms 254 from their respective master cams 238. The other side of thewheel-pressure cylinder 244 is then exhausted by way of the hoseconnection 250, valve 626, a conduit .6112 and conduit 565, thespringurged valve element 627 in the valve 626 being then subjected atthe bottom to oil under pressure in the conduit 6 I 6 and, inconsequence, raised sufliciently to provide communication between thehose connection 255 and the conduit 612. Energization of winding 338 ofthe solenoid valve 330 at the end of an operating cycle of the apparatusand the corresponding shift of the solenoid valve 330 into thedot-and-dash line position shown in Fig. 19, results also in the exhaustof the left hand end of the valve 512, so that the latter may, under theforce of the spring 516 move into the dot-and-dash line position in Fig.19. Valve 512 is thus exhausted by way of conduit 5'10, solenoid valve330-, and conduits 6 I2, 6I4 and 566. Valve 512 now assuming thedot-anddash line position shown in Fig. 19, the top end of the work-rackcylinder I94 is exhausted by way of conduit 592, valve 572, a conduit618 and conduit 566. The lower end of the cylinder I94 is subjected tooil under pressure as long as the pump 320 operates, wherefore thework-rack piston I95 and parts connected therewith are returned to theiruppermost position at the end of each operating cycle of the apparatus.Should the operator fully stop the apparatus at the end of a daysperformance or at any other time, by depressing the stop switch 346, theoil in the various lines supplied by the pump 320 will then be no longerunder pressure, with the result that the valve element 680 in the valve594 is springurged into a position in which it blocks conduit 584,whereby the oil in the lower end of the work rack cylinder I94 becomeslocked therein and retains the piston I95 in its uppermost positionwhile the apparatus is stopped completely.

Whenever the windings 340 and 342 of the solenoid valve 332 arede-energized, the sliding valve element 684 thereof is urged by balancedsprings (not shown) into the before-mentioned neutral isriiiisitioniinwhich its lands 682 .block the Jadja- I :cen'ten'dsioftheconduits 556 and 562, respectively, thereby maintaining the hydraulicmotor 3|2 for the compound applicator 290 hydraulically lockd. Thesliding ..valve element 686 in the 'otheizsolenoid lvalve 3301s,whenever both wind- .ings336 and 1338 thereof are de-energized, forcedby balanced springs (not shown) into the beforementionedneutralpositionin which the lands 610 offlthe. valve element 686 block the adjacentends. of.the conduits .610, and 510, respectively, and thus.interceptrcommunication between these condu'its.and'thezconduit 568which is in open communication withithe pump 320.

" 'Rsiiiitefof operation m Assuming. thatthenms nt ppa atu is at. acpxnplete standstill and. that .a pa ed wor rac Bil...is.1suspended.from the ps il to f ame. J. 5 r the. mannenbestsho n in i efie f rtheassuming that the apparatus is set fora bufiing .cycle,.. the, operatorwill. then initiate, .the cycle jlgy first throwing switch MBinto fPumpposition order to effect closureof the magnetic, starter switch..362and, hence, closure of the circuit of the;pump motor 322, allaspreviously.. described. operation of the pump 326 results in the. build-.up of oil under pressurein. the various oil lines thatlead to thehydraulic. devices oftheappa- .ratus. However, these oil lines are atthis initial stage in an operating cycle effectively blocked from theirrespective hydraulic devices so that the continuously. flowing oilfromthe pump is at this time returned to the oil reservoir .560..past acheck valve Hi6 and through a conduitlDZ. .Simultaneously with theshift'by' the operator of the. switch 348 into Pump positionandfaccording closure of the magnetic starter switch I 362, the circuitof. the motor 324 'for'the oil cooler 326 is also closed. The operatornext shifts switch 348 from the .Pump position into the Wheel position,effectin'g thereby immediate closure of the magnetic switch 398. Theclosed magnetic switch tors 98 and I26, as previously described; The

having previ'ously been closed enclosure of the magnetic"starterswitch3'62, the startswitch 344 may, for the performance ofthe-compoundfapplicator 296, now bedepr'essed fora brief time period.Brief depressionof the start switch "'3'44 results in consecutiveclosurefof the previously described starting and holding circuits "ofthe 'winding 340 of the solenoid valve 332-, causing thereby a shift' ofthe latter into "the'fulleline p'osition'shown in Fig. '19, in whichitdirects'the flow of'oil under pressure through theh'yd'rafilib motor 3 l2 in such direction that the latter moves the "compound applicator 29Din its initial direction to the left as viewed in Figs. *1 and "3.Shortly after the compound applicator commenced to travel in the initialdirection, theair valve .223 J(Figs. l, 3 and .11) openedbythe pin 23]'on the cross head 294,'admitting'th'ereby other winding 342 ofthesolenoid'valve 332 in the then also perm t theeaiiaest' as long asthe latter ep'r'a inFigs. "14-and '19'when the frame I50 previouslydescribed manner, causing thereby 'a shift of the latter into the dotand dasli' line p'osit'i'on shown in Fig. 19 in which thesamedi rectsoilunder pressure through the hydraulicmotor 3l2 in the oppositedirection. 'The hydraulic motor 3|2 then causes return movement ofithecompound applicator 296 into home position. Shortly before the compoundapplicator reaches home position, the pin 23! onthe cross head 294shifts the air valve 2-23 into closed position-so as to withhold furthercompressed 'air from the 'sprayers 222 and render the latterinoperative.

The returning compound applicator "299 forces switch 454 into thefull-line position shownrin Fig. 18, and thereby closes the circuit ofthe winding 336 of the solenoid valve 333, provided switch 355 haspreviously been shifted to Auto" position. immediately on" closure 'ofthe circuit of the winding 33$"0fithFSO1EI10id valve 330, the latter isshifted into 'the'full' line i-position shown in Fig. '19, in which'the"same effects swinging movement of the operating wheels 60'aiid theirfollower arms -2'34.."in'to operative relation with the master cams 238,and further effects reciprocation and -oscillation of the work forapre'determined time periodiduring which the operating wheels 60performthe desired bufiing-opera- .tion on the opposite side edges ofthe knife handles while the same remain inoperative engagement withthewheelstll, as' pre'vioii'sly fully explained. More particularly;"the*s'olerui'idvalve 336 will, Whenin' the full lin'e positio'fi showFig; 19, eifect a *shift-of"thecontrol valve 12 into the full lin'e'posi-tion, which bitfii'fi dr pressure is admitted throiig h the latterto the top end "of the 'work racknylind'er 194 to asset the first andfull downstroke of the worknam uppermost position. Tasmania valve i331)will then also provide' coiiir'nunication Between the exhaust conduitsacc aim em urine 'workoseillatin'g' motor "202' and I the exhaustconduits 612, 6M and 5'56,"therehy and permitting "th under pressureflowing through the o' dl lit" 6 9 6 (Fig; "19) I g the right hand sideof the wheel pressure 6;? n "r24 tragic), with the re ultthiatfiilii-nd'erpres'sure "till now be admitted into 'thothel is'id bf "the"2'44 and'the fol-lowerarifis' fl l of the op rating wheels'fifl'willbebrou'gl it into cp'rati-v re with the "master cams 238. The 1 "wer theworli ra'ckcylirider 94*is perrn jecte'd to asunder-pressure rsm theviously "explained. "-However,*on=in1tial "si'on of "oil "underpressurtfito the upper 'en'd 'f6f the cylinder 19-4, in conseiiueriee ofth shift f the valve 512 into the run: rieposi n 'iiowjh m Fig. :19;the' oil displaced from the r wer end of the *cylinder 194 ;by thedescending piston I35 therein is bypassewto'the top fendof the' safiie'cylinder thrdughconiiuit 3d wit the i'riterposed valve 594, conduit586, awe-tea; eciiduit sst, valve 5'l2=,=and 'conduit 5'92. I t

, :The pilot valve 640 'assu-me's the pcsitiomshh'wn fact thatthe pilotvalve has been" hi "ed "intb this position bythefrairfe it'llenirsaeefit izitb uppermostpositionat tne en'd df t1ie fieced ih cycleof operation of the apparatus. Toward the end of the initial and fulldownward stroke of the frame I58, the lug 636 thereon will shift thepilot valve 648 from the position shown in Fig. 14 into the positionshown in Fig. 16, in which the same admits oil under pressure from theconduit 558 through the conduit 664 into the right hand end of the valve588, causing thereby a shift of the latter from the full-line positioninto the dot-and-dash line position shown in Fig. 19, in which the topend of the work-rack cylinder I94 is permitted to exhaust by way ofconduit 592, valve 512, conduit 598, valve 588, and conduit 566. Thework-rack piston I95 will then reverse its stroke and move upwardly,this by virtue of the fact that the lower end of the workrack cylinderI94 is continuously subjected to oil under pressure from the pump 328.When the frame then nears the adjusted limit of its partial upstroke,the lug 638 thereon will engage the finger 648 of the valve actuator 646and turn the pilot valve 648 back into the position shown in Figs. 14and 19, in which the same effects a renewed down stroke of the work-rackpiston I95, as will be readily understood. Thus, the work will continueto reciprocate and oscillate while remaining in operative engagementwith the wheels 68, until the timer 352 opens in the previouslydescribed manner the circuit of the winding 336 of the solenoid valve338, and simultaneously closes the circuit of the winding 338 thereof.Closure of the circuit of the winding 338 causes a shift of the solenoidvalve 338 from the full-line position into the dot-and-dash lineposition (Fig. '19) in which conduit 518 is exhausted by way of valve338 and the conduits 6I2, GM and 566, with the result that element 514in the valve 572 is spring-urged into the dot-and-dash line position(Fig. 19) in which the top end of the work-rack cylinder I94 ispermitted to exhaust by way of conduit 592, valve 512, and conduits 618and 566. When in the dot-and-dash line position, the solenoid valve 338also provides communication between the conduit 568 that carries oilunder pressure, and the conduit 6I8 and branch conduit 688, therebycausing the work-oscillating motor 282 to become hydraulically locked,and causing thewheel pressure cylinder 244 and piston therein towithdraw the follower arms 234 of the operating wheels 68 from theirrespective master cams 238, all as previously described in detail.

A repeat buffing cycle of the apparatus may, after replacement of thework therein, be started by depressing the start switch 344. The repeatcycle that will then take place starts immediately with a performance ofthe compound applicator 298, and the cycle itself is exactly the same asthe previously described initial cycle starting with the performance ofthe compound applicator thereof. Immediate performance of the compoundapplicator in this and any following repeat cycle is due to the factthat the pump motor 324 and the wheel motors 98 and I26 keep on runningbetween intermittent stops of the apparatus, and will stop only if theoperator depresses the stop switch 346, all as previously described.Hence, the present apparatus may perform as many repeat cycles as aredesired, each repeat cycle to be started by merely depressing the startswitch 344.

In order to bring the apparatus to a full stop at the end of a daysperformance or at any other time, the operator need merely depress thestop switch 346 momentarily, as will be readily understood from thepreceding description. If the operator should, in the course of anoperating cycle of the apparatus, detect faulty performance of theoperating wheels 68 on the work, or notice any other abnormal conditionthat may be, or threatens to be, harmful to the work or to the operatingparts of the apparatus, the operator may arrest the reciprocation andoscillation of the work in any instant position, by shifting switch 358from Auto position to "Stop position. In the latter event, it may bedesired to bring the work in the apparatus to its uppermost position, inwhich case the operator need merely shift switch 258 into the Raiseposition.

If the present apparatus is to be used for trimming purposes, thebuffing wheels are replaced by trimming wheels, and switch 428 isopened. The opening of the switch 428 eliminates in each trimming cyclea performance of the compound applicator 288. With this singleexception, a trimming cycle of the apparatus is exactly like a buffingcycle thereof.

While we have shown and described a preferred embodiment of ourinvention, it will be understood that various changes may be made in the-present invention without departing from the underlying idea orprinciples of the invention within the scope of the appended claims.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

1. In apparatus of the character described having a rotary buffingwheel, and a carrier removably holding work and being reciprocable tomove the work to and from operative engagement with said wheel, thecombination of a rotatably mounted threaded spindle extendingsubstantially parallel to said wheel, a buffing compound applicatornon-rotatably mounted on, and in threaded engagement with, said spindleso as to move axially on said spindle when the latter rotates, and meansfor driving said spindle in either direction to move said applicatorthereon along said wheel in compound-applying relation therewith.

2. The combination in apparatus as set forth in claim 1, in which saidspindle driving means comprise a reversible hydraulic motor drivinglyconnected with said spindle, and control means operable to direct fluidunder pressure through said motor in opposite directions, respectively.

3. The combination in apparatus as set forth in claim 1, in which saidspindle driving means comprise a reversible hydraulic motor drivinglyconnected with said spindle, and a valve normally assuming a neutralposition and shiftable into two operating positions in which to directfluid pressure through said motor in opposite directions, respectively,said valve intercepting the flow of fluid under pressure to said motorwhen in its neutral position.

4. The combination in apparatus as set forth in claim 1, in which saidspindle driving means comprise a reversible hydraulic motor drivinglyconnected with said spindle, a valve normally assuming a neutralposition and shiftable into two operating positions in which to directfluid under pressure through said motor in opposite directions,respectively, said valve intercepting the flow of fluid under pressureto said motor when in its neutral position, solenoid windings adapted,when energized, to shift said valve into said operating positions,respectively, and a separate circuit including a switch, for eachsolenoid winding.

5. In apparatus of the character described

